New York ? If you think only of pearls as small, white and perfectly round baubles mostly worn by grandmothers and brides, a new exhibit at the American Museum of Natural History will open your eyes.

“Pearls” features everything from a bright orange pearl twice the size of a marble to one that was so oddly shaped that a jeweler during the Renaissance fashioned it into a golden pendant depicting a wounded lion.

A huge brooch worn by a Scottish gentleman is decorated with pearls, as is a religious chalice from the time of the Crusades and a Nepalese king’s crown.

And then there is the jaw-dropping pear-shaped pearl found by a slave in the Gulf of Panama in the 16th century. The slave was given his freedom, and the pearl passed through a succession of royal hands before ending up in a necklace given to actress Elizabeth Taylor by Richard Burton as a Valentine Day’s present.

But the exhibit does not focus only on pearls incorporated into jewelry.

It examines the dangerous job of pearl diving with the use of video and the clunky equipment divers wore. It demonstrates how pearls can come from any freshwater or ocean-dwelling mollusk that produces a shell even snails and how the color and size of the shell influences the color and size of the pearl.

Neil H. Landman, the show’s lead curator, worked for three years to pull the exhibit together from more than 100 institutions. He said he was inspired by earlier exhibits at the museum on diamonds and amber.

“These wonderful natural materials tell a great story from a natural history point of view as well as a cultural point of view,” Landman said. “Rather than have a whole section just on natural history of pearls and whole section just on culture, we intertwine them throughout. It’s a really good marriage.”

Landman, a curator in the museum’s division of paleontology, admitted having a favorite piece of jewelry: a platinum and diamond chrysanthemum brooch, in which each petal is represented by a dogtooth-shaped, creamy-colored freshwater pearl. Made by Tiffany & Co. in 1904, it is to Landman “the greatest combination of artistry and natural history.”

“Pearls” is on show at the American Museum of Natural History through April 14. It goes on display at the Field Museum in Chicago June 28 through Jan. 5, 2003.